Double bar jordan plug



B. E. PREVOST 3,004,725

DOUBLE BAR JORDAN PLUG Filed Sept. 9, 1959 I, 22 o J I INVENTOR.

BRUNO E. PRE'VOS'T BY 'PM *7 m ATTORNEYS 3,004,725 DOUBLE BAR JORDANPLUG Bruno E. Provost, West Boxford, Mass., assignor to John W. Bolton &Sons, 1110., Lawrence, Mass, at corporation of Massachusetts Filed Sept.9, 1959, Ser. No. 838,900 6 Claims. (Cl. 241-294) This invention relatesto an improved plug for a rotary refiner of the dovetail groove, doublebar type.

It has long been customary in the trade to provide an expansible fillerbetween the pair of bars in each groove and to provide an expansibleseparator between the pairs of bars in adjacent grooves. Usually thebars have been formed of steel rolled to a special shape with enlargedshoulders, ribs and the like for anchoring the parts as in U.S. Patent341,223 to Clawson of May 4, 1886, or US. Patent 2,862,424 to Jones ofDecember 2, 1958. It has also been proposed to use bars of rectangularcross section and uniform thickness, there being spaced shoulders on thelower portion of the bars fitting the undercut wall of the groove orfitting under a ring as in US. Patent 1,362,606 to Dorman of December21, 1920, US. Patent 243,733 to Smith of July 5, 1881, or US. Patent349,332 to Anderson of September 21, 1886.

While any and all of the structures of the above specified patents serveto anchor one or more of the parts in the groove, it is the expansibleseparators between the pairs of bars that usually are locked in placeonly by friction or by providing a divergent face on the bars. Thelatter system of anchoring the separators not only requires a relativelyexpensive rolled bar but also takes up considerable space, especiallywhen the bars are closely packed and at the small end of the truncatedconical I plug.

It is the object of this invention to provide a grooved, double bar plugin which the bars are of flat, thin, unmachined metal, available atrelatively low cost, but are provided with spaced, elongated shouldersfor metal to metal engagement with the undercut wall of the groove, onlythe flat face of the shoulder being machined into a smooth, fiat face.

Another object of the invention is to provide a grooved, double bar plugin which the bars include spaced, ma-

chined shoulders for anchoring the bars in the grooves and also includespaced protuberances therealong for anchoring keystone shaped separatorsbetween the pairs of bars.

A further object of the invention is to provide a grooved, double barplug with expansible keystone shaped separators between the pairs ofbars, the separators having grooves in the side walls thereof slidableon rows of protuberances on the bars whereby they cannot be dislodgedradially by centrifugal force even before swelling in the paper stock.

Still another object of the invention is to provide a novel low costJordan plug of the grooved type wherein ordinary bar metal is used forthe knives and anchoring is achieved by low cost punching operationsupsetting the metal of the bar into a lower row of shoulders and anupper row of protuberances.

Other objects and advantages of the invention will be apparent fromtheclaims, the description of the drawing and from the drawing in which aspecific embodiment is illustrated.

FIG. 1 is a perspective view of a refiner plug constructed in accordancewith the invention,

FIG. 2 is an enlarged, exploded, fragmentary View, in perspective of thebars, fillers and separators of the invention, and

FIG. 3 is an enlarged, fragmentary, end view of the plug shown in FIG.1.

United States Patent i. 3,004,725 Cfi Patented Oct. 17, 1961 In thedrawing 20 is a Jordan plug of the usual frusto conical shape andcomprising a plug body 21 having a plurality of longitudinally extendinggrooves such as 22, 23 and 24 each of undercut or dovetail crosssection. Plug 20 also includes the large end 25, the small end 26 andthe shaft 27. The alternate grooves 22 and 24 extend the full length ofthe plug body 21 while the alternate grooves such as 23 extend only partway along the plug body because of space limitations at the small end26. End rings such as 28 are detachahly mounted at each end of plug body21 for securing the bars against longitudinal movement and the surfaceof the plug body is designated 29.

It will be understood that the showing of FIG. 1 is not to scale andthat actually the grooves are quite close together with the barsrelatively closely packed. The enlarged showing of FIGS. 2 and 3 is amore accurate rep resentation of the relative dimensions of the plugbars and grooves. FIG. 3 represents the spacing at the large end of theplug, the grooves 22, 23 and 24 converging toward each other whereby, atthe small end, the full length grooves 22 and 24 are closely juxtaposed.

As best shown in FIG. 2 the pair of bars 31 and 32 are identical andback to back and formed of 'unrolled, unmachined metal of rectangularcross section and uniform thickness. Such bar material is commerciallyavailable at low cost and in any desired dimensions. Each bar isprovided with a row of longitudinally spaced apart shoulders such as 33and 34 formed by upsetting the material of the bar by punching inanother low 'cost operation. Unlike the curved, or hyperboliform, facesof the above specified Anderson patent or the right angular lockingfaces of the above specified Dorman and Smith patents, the anchoringface 35 of each shoulder 33 or 34 is elongated, downwardly inclined,flat and smooth and is the only portion of the bar which is machined bymilling. Each anchoring face 35 of each shoulder 33 or 34 is in metal tometal engagement with a metal undercut face 36 or 37 of a groove such as22 and, since it is fiat and smooth, an accurate fit is achieved. Theend Walls 38 or 39 of each shoulder are slightly curved but generallyright triangular in outline whereby the shoulder resembles an inclinedbuttress and broadens the base of the bar where it is seated in thebottom 41 of the groove.

. of. Each protuberance 44 or 45 is upset from the material of the barby punching, thereby forming a corresponding row of recesses such as 47on the inner faces 42 of the bars. Each protuberance 44 or 45 includes acurved face 48 and a pair of opposite faces 49 and 50 at right angles tothe outer face 46, the cross section of the central portion of theprotuberance being rectangular in configuration. As shown, theprotuberances 44 and 45 are each staggered with relation to theshoulders 33 and 34 and located above the space therebetween.

A relatively thin filler 52 of rectangular cross section and formed ofexpansible material such as wood is seated in each groove between eachpair of bars 31 and 32. A pair of bars 31 and 32 with a filler 52therebetween may be slid endwise into the groove as a unit, with theanchoring faces 35 in engagement with the undercut spaces 36 and 37 ofthe groove. When the plug is immersed in liquid such as paper stock, thefiller swells sufficiently in a circumferential direction to firmly lockthe bars in place against the stress and strain and centrifugal forceencountered during refining.

Between each pair of bars an expensible separator 53 tangular crosssection in each opposite side face 57 and 58 thereof. The separators 53are slid endwise into place with the bottom face 54 thereof seated onthe surface 219 of plug body 21 and the grooves 55 and 56 mounted on therows of protuberances 44 and 45 of the bars 31 and 32 and are therebyanchored against outward movement due to centrifugal force beforeswelling. Upon swelling of the separators a frictional anchoring effectis achieved and any possibility of a separator flying out of the plugassembly is eliminated.

The filler 52, upon expansion by swelling, becomes more firmly securedin place by reason of the portions adjacent the recesses 43 and 47swelling into the recesses.

The row of shoulders 33 and 34 and corresponding recesses 43 upset fromthe material of the bars 31 and 32 thus forms means for not onlyanchoring the bars in the grooves but for also firmly anchoring thefillers 52 between the bars. The row of protuberances 44 and 45 formsmeans for anchoring the grooved separators 53 between the pairs of barsand forms an additional means for retaining the fillers 52 by reason ofthe recesses 47.

I claim:

1. A plug for a rotary refiner comprising a plug body having a pluralityof angularly spaced, longitudinally extending grooves of dovetail crosssection in the surface thereof; a pair of plug bars seated in each saidgroove, each bar being of rectangular cross section and having a fiatinner face, a plurality of individual shoulders upset from the materialof said bar and spaced longitudinally along the lower, outer side facethereof, each shoulder having a flat, downwardly inclined, smoothanchoring face accurately fitting and engaging the undercut walls of thedovetail groove in which said pair of bars is seated and a plurality ofindividual protuberances upset from the material of said bar and spacedalong the intermediate, outer side face thereof for engagement withcorresponding grooves in a separator; a narrow, expansible filler ofrectangular cross section seated in each groove between the adjacentflat inner faces of the bars in said groove and a wide, expansible,separator of keystone cross section seated on the surface of said plugbody between the intermediate outer side faces of each adjacent pair ofbars, each said separator having a continuous groove along each oppositeside face thereof for slidably receiving the longitudinally spacedprotuberances on the adjacent face of said bars for retaining saidseparators against outward radial movement.

2. A combination as specified in claim 1 wherein each said fillerextends outwardly beyond the protuberances in said bars and each saidbar includes recesses in the fiat inner face thereof, at each shoulderand protuberance, into which said expansible filler canswell and expand.

3. In a Jordan plug of the undercut dovetail groove type, thecombination of a pair of plug bars arranged at a spaced distance apartin each said groove, said bars being parallel and each of rectangularcross section; a flat inner face on each said bar having a lower,longitudinally extending row, and an intermediate longitudinallyextending row, of individual, spaced apart recesses therealong; a flatouter face on each said bar having a lower, longitudinally extending rowof individual, spaced apart shoulders therealong, each having a fiat,downwardly inclined, machined face anchored under the adjacent wall ofsaid undercut dovetail groove and an intermediate longitudinallyextending row of individual spaced apart protuberancestherealong; anarrow expansible filler of rectangular cross section seated in saidgroove in engagement with the inner faces of the pair of bars in saidgroove for locking said bars therein by circumferential expansion, saidfiller having a plurality of longitudinally spaced portions expandedinto said rows of recesses and a wide, expansible separator of keystonecross section between each adjacent pair of bars in said grooves, eachsaid separator having a longitudinally extending continuous groove ineach opposite side wall thereof slidably mounted on the row ofprotuberances of the adjacent bar of each pair forretaining saidseparator against radial,

' outward movement.

4. A combination as specified in claim 3 wherein each said protuberanceincludes an upper and a lower flat face at right angles to the adjacentface of said bar and a curved side face.

5. A combination as specified in claim 3 wherein said protuberancesandsaid shoulders are uniformly staggered along said bars with theprotuberances above the spaces between said shoulders.

6. In a Jordan plug of the undercut dovetail groove type the combinationof a pair of plug bars arranged at a spaced distance apart in each saidgroove, said bars being parallel and each of rectangular cross section;a narrow expansible filler of rectangular cross section seated in eachsaid groove between the bars therein, a wide expansible separator ofkeystone cross section seated on the surface of the plug between eachadjacent pair of bars in said grooves, said separators each havingcontinuous grooves in the side faces thereof; first longitudinallyspaced means punched in the material of the lower portion of said barsfor anchoring the same in said undercut grooves and anchoring saidfiller therebetween and second longitudinally spaced means punched inthe material of the intermediate portion of said bars for anchoring saidseparators between adjacent pairs of bars.

References Cited in the file of this patent UNITED STATES PATENTS727,176 Mills May 5, 1903 1,362,606 Dorrnan Dec. 21, 1920 2,709,396Bridge May 31, 1955

